linux-kernel - Re: [PATCH] drm/exynos/hdmi: Don't print error on deferral due to regulators

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Message-id: <5719B66E.9000703@samsung.com>
Date:	Fri, 22 Apr 2016 07:28:14 +0200
From:	Krzysztof Kozlowski <k.kozlowski@...sung.com>
To:	Javier Martinez Canillas <javier@....samsung.com>,
	linux-kernel@...r.kernel.org
Cc:	Kukjin Kim <kgene@...nel.org>, linux-samsung-soc@...r.kernel.org,
	Seung-Woo Kim <sw0312.kim@...sung.com>,
	dri-devel@...ts.freedesktop.org, Inki Dae <inki.dae@...sung.com>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	David Airlie <airlied@...ux.ie>,
	Joonyoung Shim <jy0922.shim@...sung.com>
Subject: Re: [PATCH] drm/exynos/hdmi: Don't print error on deferral due to
 regulators

On 04/21/2016 08:51 PM, Javier Martinez Canillas wrote:
> The regulators may not be available just because their driver's probe
> function was just not executed and so the regulators not registered.
> 
> So, in this case the Exynos HDMI driver should not print logs since
> a -EPROBE_DEFER is not really an error and that will just pollute
> the kernel log and confuse users.
> 
> This patch prevents the following misleading messages to be printed:
> 
> [    1.443638] [drm:hdmi_probe] *ERROR* failed to get regulators
> [    1.449326] [drm:hdmi_probe] *ERROR* hdmi_resources_init failed
> 
> Reported-by: Krzysztof Kozlowski <k.kozlowski@...sung.com>
> Signed-off-by: Javier Martinez Canillas <javier@....samsung.com>
> 
> ---
> 
> The real fix for these kind of issues is to change the device model
> core to support device dependencies so the number of probe deferral
> should be minimal or non-existent, instead of fixing on each driver.
> 
> But there have been different attempts [0,1] to implement this and
> there doesn't seem that this will be solved in the short term.
> 
> [0]: https://lkml.org/lkml/2014/5/12/452
> [1]: https://lkml.org/lkml/2015/5/25/251
> 
>  drivers/gpu/drm/exynos/exynos_hdmi.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

Since I like to look at 'dmesg -l err' then I find this useful:

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@...sung.com>

Best regards,
Krzysztof